Fuel cell, fuel cell apparatus, vehicle and co-generation system including the same and fuel cell operation method

Abstract

A fuel cell apparatus is capable of quickly heating a solid electrolyte to a proper temperature in order to perform effective electric power generation. The apparatus includes a fuel cell ( 1 ) for generating electric power by cell reacting a fuel gas on an anode-( 3 ) side with oxygen on a cathode-( 4 ) side. The fuel cell ( 1 ) includes a solid electrolyte ( 2 ) formed of a porous mass and uses a differential pressure to cause the fuel gas on the anode-( 3 ) side to permeate through the solid electrolyte to the cathode-( 4 ) side. The solid electrolyte ( 2 ) is heated by combustion reaction of the fuel gas permeated through the solid electrolyte ( 2 ) and mixed with the oxygen.

1. A solid oxide fuel cell apparatus comprising a solid oxide fuel cell for generating electric power by cell reacting a fuel gas on an anode side with oxygen on a cathode side, wherein the solid oxide fuel cell includes a solid electrolyte allowing a part of the fuel gas or the oxygen to permeate therethrough as gaseous permeation between the anode side and the cathode side, and wherein the solid electrolyte is heated by combustion reaction effected by the fuel gas or the oxygen permeated through the solid electrolyte and mixed with the oxygen or the fuel gas, the solid oxide fuel cell allowing oxygen on the cathode side to be ionized to oxygen ions and conducted through the solid electrolyte to the anode, thereby cell reacting the oxygen ions with the fuel gas on the anode side for generating electric power, the heat from the combustion reaction used for quickly heating the solid electrolyte to a power generation temperature at which the solid electrolyte is able to attain effective ion conductivity, wherein the solid oxide fuel cell apparatus further comprises a control means for controlling an intensity of the combustion by regulating the differential pressure between the anode side and the cathode side to adjust the amount of fuel gas or oxygen permeated through the solid electrolyte. 
     
     
       2. A fuel cell apparatus according to  claim 1 , further comprising control means for maintaining the solid electrolyte at temperature above a power generation temperature by controlling the intensity of the combustion of the fuel gas and the oxygen, the power generation temperature at which the solid electrolyte can attain effective ion conductivity. 
     
     
       3. A fuel cell apparatus according to  claim 2 , wherein the control means controls the intensity of the combustion of the fuel gas and the oxygen according to the ion conductivity of the solid electrolyte. 
     
     
       4. A fuel cell apparatus according to  claim 1 , wherein the solid electrolyte is a porous mass. 
     
     
       5. A fuel cell apparatus according to  claim 1 , wherein any one of the anode, the cathode and a region of the solid electrolyte of the fuel cell constitutes a combustion section. 
     
     
       6. A fuel cell apparatus according to  claim 5 , wherein the combustion section is defined as a place where flames are formed. 
     
     
       7. A fuel cell apparatus according to  claim 6 , wherein the combustion section is a cathode. 
     
     
       8. A fuel cell apparatus according to  claim 1 , further comprising ignition means disposed on the anode side or the cathode side where the combustion reaction of the fuel gas and the oxygen takes place. 
     
     
       9. A vehicle comprising a fuel cell apparatus and an operating section operating on electric power generated by the fuel cell apparatus,
 wherein the fuel cell apparatus includes a solid oxide fuel cell for generating the electric power by cell reacting a fuel gas on an anode side with oxygen on a cathode side, wherein the solid oxide fuel cell includes a solid electrolyte allowing a part of the fuel gas or the oxygen to permeate therethrough as gaseous permeation between the anode side and the cathode side, and wherein the solid electrolyte is heated by combustion reaction effected by the fuel gas or the oxygen permeated through the solid electrolyte and mixed with the oxygen or the fuel gas, the solid oxide fuel cell allowing oxygen on the cathode side to be ionized to oxygen ions and conducted through the solid electrolyte to the anode, thereby cell reacting the oxygen ions with the fuel gas on the anode side for generating electric power, the heat from the combustion reaction used for quickly heating the solid electrolyte to a power generation temperature at which the solid electrolyte is able to attain effective ion conductivity, wherein the fuel cell apparatus further comprises a control means for controlling an intensity of the combustion by regulating the differential pressure between the anode side and the cathode side to adjust the amount of fuel gas or oxygen permeated through the solid electrolyte. 
 
     
     
       10. A vehicle according to  claim 9 , further comprising:
 a fuel tank for storing a vehicle fuel; 
 a vehicle driving section operating on the vehicle fuel; and 
 a fuel feeding section for supplying a part of the vehicle fuel as the fuel gas to the anode side of the solid oxide fuel cell provided in the fuel cell apparatus. 
 
     
     
       11. A co-generation system comprising a fuel cell apparatus and means for utilizing the heat of an exhaust gas discharged from the fuel cell apparatus,
 wherein the fuel cell apparatus includes a solid oxide fuel cell for generating electric power by cell reacting a fuel gas on an anode side with oxygen on a cathode side, wherein the solid oxide fuel cell includes a solid electrolyte allowing a part of the fuel gas or the oxygen to permeate therethrough as gaseous permeation between the anode side and the cathode side, and wherein the solid electrolyte is heated by combustion reaction effected by the fuel gas or the oxygen permeated through the solid electrolyte and mixed with the oxygen or the fuel gas, the solid oxide fuel cell allowing oxygen on the cathode side to be ionized to oxygen ions and conducted through the solid electrolyte to the anode, thereby cell reacting the oxygen ions with the fuel gas on the anode side for generating electric power, the heat from the combustion reaction used for quickly heating the solid electrolyte to a power generation temperature at which the solid electrolyte is able to attain effective ion conductivity, wherein the fuel cell apparatus further comprises a control means for controlling an intensity of the combustion by regulating the differential pressure between the anode side and the cathode side to adjust the amount of fuel gas or oxygen permeated through the solid electrolyte. 
 
     
     
       12. A solid oxide fuel cell operating method comprising:
 generating electric power by cell reacting a fuel gas on an anode side with oxygen on a cathode side by means of a solid electrolyte, 
 supplying a part of the fuel gas or the oxygen on one side to the other side so as to heat the solid electrolyte by combustion reaction of the supplied fuel gas or oxygen with the oxygen or the fuel gas, the solid oxide fuel cell allowing oxygen on the cathode side to be ionized to oxygen ions and conducted through the solid electrolyte to the anode, thereby cell reacting the oxygen ions with the fuel gas on the anode side for generating electric power, the heat from the combustion reaction used for quickly heating the solid electrolyte to a power generation temperature at which the solid electrolyte is able to attain effective ion conductivity, and 
 controlling an intensity of the combustion by regulating the differential pressure between the anode side and the cathode side to adjust the amount of fuel gas or oxygen permeated through the solid electrolyte. 
 
     
     
       13. A fuel cell operating method according to  claim 12 , wherein the solid electrolyte is heated by the combustion reaction when the fuel cell starts up.